<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8" />
  <title>圣杯布局</title>
  <style>
    #bd {
      padding: 0 200px 0 180px;
      height: 100px;
    }

    #middle {
      float: left;
      width: 100%;
      height: 500px;
      background: blue;

    }

    #left {
      float: left;
      width: 180px;
      height: 500px;
      margin-left: -100%;
      background: #0c9;
      position: relative;
      left: -180px;
    }

    #right {
      float: left;
      width: 200px;
      height: 500px;
      margin-left: -200px;
      background: #0c9;
      position: relative;
      right: -200px;
    }
  </style>
</head>

<body>
  <div id="bd">
    <div id="middle">middle</div>
    <div id="left">left</div>
    <div id="right">right</div>
  </div>
</body>

</html>